Absorption Cross-Section and Decay Rate of Dilatonic Black Strings

TL;DR

This paper analytically investigates the propagation of a tachyonic scalar field around a 5D dilatonic black string, deriving explicit formulas for greybody factors, absorption cross-section, and decay rate, with results illustrated for various parameters.

Contribution

It provides the first exact analytical expressions for greybody factors, absorption cross-section, and decay rate of a tachyonic scalar in a 5D dilatonic black string background.

Findings

Exact solutions for the Klein-Gordon equation in 5D dilatonic black string

Analytical formulas for greybody factor, absorption cross-section, and decay rate

Graphical analysis of parameter effects on results

Abstract

We studied in detail the propagation of a massive tachyonic scalar field in the background of a five-dimensional ($5D$) Einstein--Yang--Mills--Born--Infeld--dilaton black string: the massive Klein--Gordon equation was solved, exactly. Next we obtained complete analytical expressions for the greybody factor, absorption cross-section, and decay-rate for the tachyonic scalar field in the geometry under consideration. The behaviors of the obtained results are graphically represented for different values of the theory's free parameters. We also discuss why tachyons should be used instead of ordinary particles for the analytical derivation of the greybody factor of the dilatonic $5D$ black string.